Safety device for oil-burning systems



May 22, 1923. I H. A. TEDMAN SAFETY DEVICE FOR OIL BURNING SYSTEMS Original FiledJune 2l 1921 I Zh w67@ for:

Patented May 22, 1923.

HUDSON A. TEDMAN, OF GALESBURG, ILLINOIS, SSIGNOR T0 WINSLOW BOILER & ENGINEERING COMPANY, 0F CHICAGO, ILLINOIS, A-CORPORTION 0F ILLINOIS.

SAFETY DEVICE FOR OIL-BURNING SYSTEMS.

Application led'J'une 21, 1921, Serial No. 479,223. Renewed March 15, 1923.

To all whom t may concern Be it known that I, HUDSON A. TEDMAN, a citizen of the United States, residing at Galesburg, in the county of Knox and State of Illinois, having invented certain new and useful Improvements in Safety Devices for `Oil-Burning Systems, do hereby declare that the following is a full, clear, and exact description of the same, reference being had to the accompanying drawings.

The invention relates to certain new and useful improvements in safety-devices for oil burning systems, and its primary object is to provide an improved apparatus for safely producing a periodical iame from a mixture of air and atomized oil, and particularly means for automatically stopping the motor and the supply of fuel-oil to the burner in case the system fails tofunction, as for example if the -oil is not suficiently atomized or the air ysupply is insufficient to provide a combustible' mixture of oil and air,

or if the ignition device does not ignite the fuel mixture.

In oil burning systems or plants using heavy grades of fuel-oil the oil is atomized` and mixed with a supply of air to form the combustible mixture, which then is ignited by a suitable pilot light or electric spark, and as these systems are usually intermittent in their heating action on the steamgenerator or boiler, operating in accordance with the varying thermal conditions in the device being heated they are usually provided with means for periodically starting and stopping the motor that drives the blower to supply the combustion air to the burner. However, these means do not otherwise control the system and if there is a failure to produce or ignite the combustible mixture in the burner when an operative period occurs the fuel-oil continues to How to the burner. n

My inventionprovides improved means for automaticallyv stopping the motor and ow of fuel-oil to the burner after a small quantity' of this oil has passed to the burner under any condition that fails to produce a combustible mixture or ignite it, and so prevents the accidental accumulation or waste of oil and the danger of explosion of the vapor arising from its natural vaporiza` tion in the restricted areal of the fire-box or boiler-room. v

In the accompanying 'drawings Fig. 1. is

of a form of electro-magnetic valve that i may be employed.

n indicates a combustion-chamber or fire-pot of suitable size and shape to conform to the design ofthe associated steam-boiler, and to which fuel-oil is supplied by a fuel-pipe 2. A low-pressure blower 3 is mounted ona base-plate et and is provided With an air tube 5 which is connected at its outlet to the fire-pot to furnish the combustion-supporting air; the air-tube preferably is divided at its outlet into two branches or conduits arranged tangentially to the interior of the fire-pot to deliver air to the pot in two lateral streams on opposite sides of the nozzle 6 of the fuel-pipe 2. The conduits are suitably connected to there-pot, and these parts are provided with supports 7 and 8.

The blower is driven by an electric motor 9, which is mounted on the base t and is connected .in an electric circuit 10 having any suit-able source of current, and the circuit may be controlled to start and stopl the motor by any usual device such as the switch Sl, which may be operated by hand or any suitable means operating in accordance with varying thermal conditions in the device being heated. When fuel-oil is supplied to the fire-pot through the pipe 2 and the motor is operated theblower or fan 3 delivers a sufficient quantit of air through'the tube 5 to mix with t e oil to form. a readily combustible mixture and ensure perfect combustion of the fuel s0 the drawings the reference numeral 1 foI'IAI'led. The oil is discharged into the re- I pot from the nozzle 6 and preferably falls upon an inclined distributing and Vaporizing plate 11 located near the bottom of the pot by which it is broken-up and atomized. The vaporized oil mixes with the infiowing air to form a fuel mixture which is readily ignited by a gas-burner 12 which is located under the plate 11 and is connected to a suitable source of gas-supply by'a'pipe 13. The distributer plate .is preheated by the lighting flame so that the initial oil falling on it' is more quickly and thoroughly vaporized to accelerate'its mixture with the air andy facilitate the lighting and burning of the fuel, and it is heated by the combustion of the fuel in the pot so that the oil falling upon it during the operation of the burner is vaporized b-y it. r1`he plate is preferably perforated to allow the oil to drip through to further break it up in contact with the lighting-flame, while the air passing into the. pot also atomizes the oil; the fuel mixture is readily ignited and continues to burn as lon as the oil is supplied to the pot.

51e bottom of the burner slopes or is inclined so that all oil that collects in it supply is inadequate or the gas-flame at the igniting burner is not burning when the fuel-oil is flowing into the pot7 the oil will low from the sump through the drain pipe into a drip or overflow pan 16 which islocated below the level of the sump. This pan is suspended on one arm ofa bell-crankv lever 17 pivoted on a bracket 18 on the base and having a tri ger arm 19 to engage a dog 20 on one en of a switch-lever 21 pivoted on a bracket 22 on the base andcarrying an adjustable weight 23 at one side of its pivot and at its other side the movable element 24,0f an electric switch 25 which is located in the circuit supplying current to the motor so that the latter may be cut into and out of the circuit when the switch is operated. When the overflow is partly filled with oil its weight or overload rocks the lever 17 to trip the trigger 19 and release the dog, whereupon the weight 23 moves the lever 21 to open the switch 25 to stop the motor.

This safety device may be set to operate upon the accumulation of a slight quantityv of oil in the pan and after it operates the pan is emptied and the parts are restored to their normal positions with the dog in enga ement with the trigger-arm and the switc 25 closed to allow current to pass to the motor when the main switch S controlling the circuit is properly set. y

An electrically operated oil-valve is located in the fuel-oil line in order to shut ofl'.' all oil to the burner, and is`V operated by Vthe electric current that operates the motor,

the parts being arrangedso that the valve is opened to permit the How of oil to the burner as long as the safety device is inoperative and is closed to positively shutot the supply of oil to the burner when that vdevice operates. This valve may be of any suitable construction, and in the drawings I show a practical form in Fig. 3.

The case 26 of the electro-magnetic valve shown is supported near the vair-tube and preferably has a pipe 27 communicating therewith to furnish air to the interior and a perforated cap plate 28 to provide ventilation, so that circulation of air through the case to cool its magnet is assured by the draft through the tube. The valve body is formed by acup-sliaped block 29 located in one end of the case and pro-vided in its lower portion with the opposite inlet port 30 and outlet port 31 screw threaded for the connection of the oil inlet pipe 32 and the outlet pipe 2 which pass through opposite sides of the case. rlhe block is provided in its upper portion with a valve chamber 33 which is closed by a brass cover plate 34 attached to the inner end of the block by screws 35 as shown. The inlet po-rt 30 opens into the chamber, and the central portion of the block projects into the chamber a short distance to form an upward extension which is shouldered to receive a screen 36 which is held in place by a ring 37. The central extension of the block is provided with an oil passa e 38 leading from the portion of the cham er above the screen into the outlet port 31, and the upper end of this passage is formed as a seat for the valve 39 which is mounted on the stem 40. The plate 34 is provided with a guide-way for the upper end of the valve stem, and a steel disk or armaturel 41 is carried by the stem, being located a suitable distance below the plate so that the armature and valve may move up to open the oil passage. The upper end of the case is provided with a cross-barl 42 which carries a screw 43 by which a suitable laminated core 44 of an electro-magnet 33 through the passage 38 to the outlet port and pipe 2. When the motor stops the magnet is de-energized and the armature and valve fall by gravity so that the latter closes the passa-ge to the oil outlet port.

The arrangement of parts for synchronously starting orstopp-ing the motor and energizing or de-energizing the magnet to control the cutfof valve 39 may be varied; I prefer to positively and directly control this valve from the safety device itself, and so connect its magnet coils to the source of current through the switch 25. This organization stops the flow of oil when operative conditions in the plant are adversely ail'ected, and prevents the waste of o-il or its accumulation in the burner, which is alranged at a level below the sump to allow the smallest quality of oil to pass out of the fire zone and away from the boi-ler. .Also, the cut-olf valve is automatically included in the circuit by the resetting of the safety device which closes the switch 25 and when the motor is operated the valve is opened simultaneously andremains open toallow fuel-oil to iiow to the burner as. long as the plant operates to form and burn a combustible mixture, and when the safety device operates the valve positively cuts off the flow of the oil to the burner. rIhe cut-off valve prevents the smallest quantity of oil from passing to the burner when the burner is inoperative either after a sustained .run or between intermittent heating runs,fwhile the drain comprising the oil sump and its discharge pipe prevents the waste of oil or its accumulation in the re zone, and the safety trip ensures the auto-matic stopping o-f the motor and closing of the valve when operative conditions are so adversely iaffected that the fuel mixture is not produced o-r ignited. By adjusting the weight 23 toward the pivot of its lever the safety device may be set to operate by the accumulation of a small quantity of oil in the pan, and by adjusting it away from the pivot the engagement of the trip members may be practically locked to hold the pan in position to catch all oil that may escape into the burner during a prolonged period of its inoperation.

I claim:

l. In a device of the class described, a burner having a fuel-oil line, a. blower to feed air to the burner, an electrically controlled cut-olf valve located in the oil line and included in an electric circuit, and automatic connections between the valve and the burner to permit the former to close the oil line when the burner fails to function.

2. In a device of the class described, a burner having a fuel-oil line, al blo-wer to feed air to the burner, an electrically controlled cut-oil' valve located in the oil line and included in an electric circuit', a switch in the circuit, a drain for the burner, and an automatic safety trip between the drain and switch.

3. In a device of the class described. a burner having a fuel-oil line, a blower to feed -air tothe burner, an electric motor to drive the blower'in circuit with a suitable source of power, an electrically con-f trolled cut-ofi' valve located inthe oil line and included in the circuit, a switch in the circuit, a `drain for the burner, and an overload trip-device between the drain and switch.

4f. In a device of the class described, a burner having a fuel-oil line, a blower to feed air to the burner, an electrically controlled cut-off valve located in the oil line and included in a suitable circuit, a switch in the circuit, a drain for the burner, a

movable pan into which the drain discharges, and an overload trip-device between the pan and switch.

5. In a device of the class described, a

burner havinga fuel-oil line, a. blower to,

feed air to the burner, an electric motor to drive the blower in circuit with'a suitable source of power, an electro-magnetically controlled cut-off valve located in the oil line and included in the circuit, a switch in the circuit, a drain for the burner, a

pan into which the drain discharges, a lever on which the pan is suspended, a second lever controlling the switch, and a trip connection between the levers.

6. In a device of the class described, a burner having a fuel-oil 'linea blower to feed air tothe'burner, an electric motor to drive the blower in circuit'with a suit- -Iable source of power, an electro-magnetically burner to vaporize the oil, a blower to feed.

combustion-air to the burner, means in the burner t0I ignite the fuel, anfelectricallycontrolled shut-oft' valve in the oil line, circuit connections from a suitable source of electric' energy to the valve, a switch in the circuit, and connections between the burner and switch to automatically open the latter when the burner fails to function;

8. In a device of the class described, a burner having a fuel-oil line, means in the burner `tovaporize the-oil, a blower to feed combustion-air to the burner, ani electric motor to drive the blower in circuit with a suitable source 0f power, an electrically controlled cut-ofi' valve locatedA in the oil line and included in the motor circuit, a` switch in the circuit, and connections between the burner and switch to automatically open the latter to allow the valve to close the oil line when the burner fails to function.

.9. In a device of the class described, a burner having a fuel-oil line, a hot-plate in the burner to vaporize the oil, a blower to feed combustion-air t0y the burner. an electric motor to drive the blower in circuit with a suitable source of power, an

electrically opened cut-olf valve located in the oil line and included in the motor circuit,a switch in the circuit, and connections between the burner and switch t0 automatically open the latter to allow the valve to close the oil line when the burner fails to function.

10. In a device of the class described, a burner` having a, fuel-oil line and lateral air-inlets, a blower to feed air to 'the burner, an electric motor to drive the blower in circuit with a suitable source of power, a hot.- plate in the burner to vaporize the oil, an electrically controlled cut-off valve located in the oil line and included in the motor circuit, a switch in the motor circuit, a drain for the burner, and an automatic safety trip between the drain and switch.

11. ln a device of the class described. a burner having a fuel-oil line and lateral air-inlets, a blower t0 feed air to the burner, :in electric motor to drive the blower in circuit with a suitable source of power, a hotplate in the burner to vaporize the oil, an electro-magnetically controlled oil valve l0- cated in the oil line and included in the motor circuit, a switch in the motor circuit, a drainfor the burner, Aand an overload trip-device between the drain and switch.

ture.

HUDSON A. TEDMAN.

In testimony whereof l -aiX my signai 

